Various devices for cutting, grinding and fracturing hard earth formations and rock during excavations (e.g. trimming or planing floor faces, rock side faces, trenching and general building footing detailing) are known in the prior art. Such devices can be mounted on the free end of an articulated arm of a tracked or conventionally wheeled excavator or the like.
For cutting or grinding such hard earth or rock formations, usually large cutting blades or grinding drums are used. For example, cutting blades typically have a diameter of more than 1-3 meters. The cutting blades or grinding drums may comprise a steel body, such as a disc or a cylinder respectively, having a circumferential surface from which a large number of cutting or grinding teeth project. Each tooth typically is positioned in a holder which is welded onto the circumferential surface. In order to improve the properties of the cutting blade or grinding drum, the holders are positioned so that the teeth have a plurality of different orientations relative to the circumferential surface. The holders may be positioned so that the teeth are tilted to either sides of a radial plane of the steel body by an angle between 0° and 45° and typically are arranged in a lace pattern around the body.
If a holder is positioned so that a respective tooth projects from the body in a direction that lies with a radial plane of the body, typically a relatively small amount of welding material is required for welding the holder onto the circumferential surface. If the holder is tilted so that the respective tooth projects more to one side of the radial plane, typically a larger gap having wedge-shaped cross-sectional profile is formed between the base surface of the holder and the circumferential surface of the body. Due to the larger gap more welding material is required for welding the holder onto the body which is detrimental for the structural strength. There is a need for technological advancement.